Dramatisation of the 1958 novel. Originally broadcast in 3 parts, all three have at some stage been merged into a single file.
Jacko Argyle dies in prison while serving a sentence for killing his adoptive mother Rachel Argyle. His own widow, Maureen, believed him to have been responsible. Jacko's alibi failed when police could not find the man who had given him a ride to the next town as the murder was happening. Two years later, Jacko's alibi suddenly appears and the family must come to terms not only with the fact that Jacko was innocent, but also with suspicion falling upon each of them as the real murderer. Some realize there is a murderer living among them, raising tensions among the family. Suspicions fall on his father, his brother, his sisters, even his father’s secretary and the long-time housekeeper, as the new investigations proceed.
The witness, Arthur Calgary, was unaware of the trial and thus failed to come forward. He believes the Argyle family will be grateful when he clears their son's name but fails to realise the full implications of the information he provides. However, once he does so, he is determined to protect the innocent by finding the murderer.